gamma for monatomic gas code example

Example: gamma gamma fitter

# refit the BG model to the summary_with_money_value dataset
bgf.fit(summary_with_money_value['frequency'], summary_with_money_value['recency'], summary_with_money_value['T'])

print(ggf.customer_lifetime_value(
    bgf, #the model to use to predict the number of future transactions
    summary_with_money_value['frequency'],
    summary_with_money_value['recency'],
    summary_with_money_value['T'],
    summary_with_money_value['monetary_value'],
    time=12, # months
    discount_rate=0.01 # monthly discount rate ~ 12.7% annually
).head(10))
"""
customer_id
1      140.096211
2       18.943467
3       38.180574
4       38.180574
5       38.180574
6     1003.868107
7       28.109683
8       38.180574
9      167.418216
10      38.180574
Name: clv, dtype: float64
"""